The present invention relates to message handling.
In message handling systems, it is known to provide a mechanism to store shared messages using a coupling facility comprising an associated queue as the shared storage.
The use of a coupling facility provides for high availability as even if a component (e.g. messaging software) associated with a computer system connected to the coupling facility fails, messaging software residing on other computer systems can still access the coupling facility. Furthermore, a coupling facility is fast, providing for improved performance.
However, the relative cost of such storage makes its use for storing large messages prohibitive.
Furthermore, some coupling facilities have a cap associated with size of a message, such that messages having a size exceeding the cap cannot be stored in the coupling facility.
One solution to this problem is detailed in US-2006-0200516-A1 wherein a data processing system for message handling comprises a coupling facility for receiving messages, the coupling facility arranged to maintain a queue of messages, and a database for storing messages. A component, such as a server, of the system is arranged to detect that a message is of a size above a predetermined threshold, and stores this larger message in the database and enters a proxy in the queue of messages.